feat: let the current assignee reassign a pending task

Keep the same task id, move the pending inbox, and record TASK_REASSIGNED without advancing the step.

Co-authored-by: Cursor <cursoragent@cursor.com>

ordo-storage-jdbc/src/main/java/com/jetlumen/ordo/storage/jdbc/JdbcApprovalTaskRepository.java

@@ -27,7 +27,9 @@ public final class JdbcApprovalTaskRepository implements ApprovalTaskRepository
                     + " VALUES (?, ?, ?, ?, ?, ?, ?)";
     private static final String COMPLETE_IF_PENDING =
             "UPDATE ordo_approval_task SET status = ?, completed_at = ?, action_actor = ?, action_comment = ?, action_at = ?"
-                    + " WHERE id = ? AND status = 'PENDING'";
+                    + " WHERE id = ? AND status = 'PENDING' AND assignee = ?";
+    private static final String REASSIGN_IF_PENDING =
+            "UPDATE ordo_approval_task SET assignee = ? WHERE id = ? AND status = 'PENDING' AND assignee = ?";
     private static final String SELECT_TASK =
             "SELECT " + TASK_COLUMNS + " FROM ordo_approval_task WHERE id = ?";
     private static final String SELECT_BY_INSTANCE =
@@ -119,6 +121,24 @@ public final class JdbcApprovalTaskRepository implements ApprovalTaskRepository
         }
     }
 
+    @Override
+    public boolean reassignIfPending(String taskId, String expectedAssignee, String newAssignee) {
+        Objects.requireNonNull(taskId, "taskId must not be null");
+        Objects.requireNonNull(expectedAssignee, "expectedAssignee must not be null");
+        Objects.requireNonNull(newAssignee, "newAssignee must not be null");
+        Connection connection = connectionProvider.getConnection();
+        try (PreparedStatement update = connection.prepareStatement(REASSIGN_IF_PENDING)) {
+            update.setString(1, newAssignee);
+            update.setString(2, taskId);
+            update.setString(3, expectedAssignee);
+            return update.executeUpdate() == 1;
+        } catch (SQLException e) {
+            throw new JdbcStorageException("failed to reassign task: " + taskId, e);
+        } finally {
+            connectionProvider.close(connection);
+        }
+    }
+
     @Override
     public Page<ApprovalTask> query(TaskQuery query, PageRequest pageRequest) {
         Objects.requireNonNull(query, "query must not be null");

ordo-storage-jdbc/src/main/java/com/jetlumen/ordo/storage/jdbc/mapper/ApprovalTaskMapper.java

@@ -40,6 +40,7 @@ public final class ApprovalTaskMapper {
             statement.setTimestamp(5, Timestamp.from(action.operatedAt()));
         }
         statement.setString(6, completedTask.id());
+        statement.setString(7, completedTask.assignee());
     }
 
     public static ApprovalTask read(ResultSet resultSet) throws SQLException {